Walter Gilbert

"[Duesberg] is absolutely correct in saying that no one has proven that AIDS is caused by the AIDS virus. And he is absolutely correct that the virus cultured in the laboratory may not be the cause of AIDS."

"The community as a whole doesn't listen patiently to critics who adopt alternative viewpoints. Although the great lesson of history is that knowledge develops through the conflict of viewpoints. If you simply have a consensus, it generally stultifies. It fails to see the problems of that consensus and it depends on the existence of critics to break up that iceberg and permit knowledge to develop. This is in fact one of the underpinnings of democratic theory. It is one of the reasons why we believe in notions of free speech and it's one of the great forces in terms of intellectual development."

"I would not be surprised if there were another cause of AIDS and even that HIV is not involved."

"I am afraid that those comments go back to the late 80's. At that time I was a skeptic — the argument based on Koch's postulates to try to distinguish between cause and association. … Today I would regard the success of the many antiviral agents which lower the virus titers (to be expected) and also resolve the failure of the immune system (only expected if the virus is the cause of the failure) as a reasonable proof of the causation argument"